DIN EN 16924:2017-08

Mycotoxins are highly harmful secondary metabolites of molds. Food that is grown, harvested or stored under humid conditions can be infested by molds, whose metabolic products are then released into the food. The toxicity of some mycotoxins is considerable for humans; safe detection is therefore of particular importance for consumer health protection. In Germany, the Mycotoxin Maximum Quantity Ordinance applies to reduce mycotoxin contamination. Since 2004, it has contained regulations not only for aflatoxins, but also for ochratoxin A, fumonisins, deoxynivalenol and zearalenone. Since 2001, the national regulations have been supplemented by EU-wide maximum levels for contaminants in food. Maximum levels of mycotoxins in certain foods are also regulated by various other ordinances. The mycotoxin zearalenone is a resorcylic acid derivative, which is produced by several species of the fungi genus Fusarium, in particular by Fusarium roseum var. graminearum. Especially cereals like maize and wheat are affected, so that zearalenone can also be detected in the oils produced from them. This European Standard describes a procedure for the determination of the zearalenone content in edible vegetable oils specifically maize germ oil by either of the following techniques: High performance liquid chromatography with fluorescence detection (LC-FLD) or high performance liquid chromatography with tandem mass spectrometry (LC-MS/MS) after basic extraction of the diluted oil. The method has been validated for zearalenone in naturally contaminated maize germ oil at levels of 61,2 μg/kg to 515 μg/kg. Laboratory experiences have shown that this method is also applicable to other vegetable oils such as wheat germ oil (n = 4), sunflower oil (n = 5), pumpkin seed oil (n = 1), soybean oil (n = 5), hemp seed oil (n = 5), rape seed oil (n = 11), and mixed oils including maize germ oil (n = 3). However occasionally, samples can result in interferences in the FLD-chromatograms. In this case, the detection with MS/MS is recommended. After diluting the edible vegetable oil, zearalenone is extracted by shaking with an alkaline methanol - ammonium hydrogen carbonate mixture. For the determination by LC-FLD, an aliquot of the centrifuged methanolic-alkaline extract is evaporated to dryness, then the residue is diluted in acidified LC-eluent and the zearalenone content is determined by LC-FLD. For the determination by LC-MS/MS, an aliquot of the centrifuged methanolic-alkaline extract is used directly for analysis. This document (EN 16924-5:2017) has been prepared by Technical Committee CEN/TC 275 "Food analysis - Horizontal methods" (secretariat: DIN, Germany) of the European Committee for Standardization (CEN) after detailed preliminary work by Working Group 5 "Biotoxins". The responsible German working committee is Working Committee NA 057-01-03 AA "Biotoxine" ("Biotoxins") at DIN Standards Committee Food and Agricultural Products (NAL).